No chainwhip? Rotafix.

http://204.73.203.34/fisso/eng/schpignone.htm

Works like a charm, and unless you have a chainwhip with a 2 foot handle, it works even better. Don't believe the BS this link gives you about not needing a lockring with it. You still do. It's just a good method for getting your cog on real snuggly.

Lockring tools are necessary, however. The only fudge you can do for that is the ol' hammer+screwdriver. Not recommended.